In any medical procedure where infection is possible, it is critical for medical personnel to be aware of and to protect the sterile field. The sterile field is an area that is considered free of microorganisms, such as bacteria and viruses. During the medical procedure, medical personnel adhere to a set of rules (or “best practices”) for protecting the sterile field. For example, the rules may require medical personnel to not touch sterile supplies with ungloved hands or other non-sterile objects (including parts of the patient), and may require medical personnel to thoroughly wash their hands before gloving.
As is typical with human behavior in general, and in particular in complex interactions between medical personnel and patients, it is not uncommon for medical personnel to violate rules due to error, or risk violating the rules for example due to rushing in emergency situations or simply poor habits. In some other situations where human error can have grave consequences, automated systems have been developed to help monitor the conditions and alert the human under risky/dangerous circumstances. Examples include collision avoidance systems for aircraft and automobiles. Similarly, for certain medical procedures, there is a need to automatically monitor the sterile field, including objects and humans in or proximal to that field, and alert the medical personnel if non-sterile objects come in contact with sterile objects or the sterile field, or risk coming into contact with sterile objects or the sterile field, for example due to close proximity of the objects.